Tubbing for tunneling devices.



UNrTn STATES PATENT FFICE.

W'ILLIAM S. MAOIIARG, CHICAGO, ILLINOIS.

TUBBING FOR TUNNELING DEVICES.

SPECIFICATION forming part of Letters Patent No. 673,852, dated 'May 7, 1901. Application filed September 3, 1900. Serial No. 28,85%. (No model.)

To all whom it may con/cern,.-

Beit known that I, WILLIAM S. MACHARG, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Tubbing for Tunneling Devices, of which the following is a specification.

My invention relates to tubbing for use in tunneling-Work.

My improvements are illustrated in the accompanying drawings, wherein- Figure l is a longitudinal section through a portion of the tubbing with the masonry shown inside and the shield outside. Fig. 2 is a cross-section through a portion of the tubbing. Fig. 3 is a detail of the Wedgeshaped key. Fig. is adetail of the we'dgingblocks.

Like parts are indicated by the same letters in all the figures.

A indicates the masonry.

B B are sections of Wood, preferably approximately eight inches square in cross-section and about two feet long. Each of these sections is grooved to receive a tongue C. D is a slot in the end of each of these sections, and there is one such slot in each end. Into these slots is received a hoop or band E. F F are somewhat similar blocks in a similar Way grooved and slotted, but of different size and having inclined opposed faces, so that they' can be driven in to tighten the sections of tubbing as they are put into place. These wedge-shaped portions would be put in at such points as to corne opposite the heads of the jacks, so that as the parts are put t0- gether the rst action of the head of the jacks is to force them into position, so as to tighten the blocks which form the sections of tubbing. H H are Wedge-shaped blocks, which together form the Wedge-shaped key-block, and they are similarly grooved and slotted. It will be understood that the size, proportion, and exact shapes of these several blocks, together with their grooves and slots, may be varied to suit convenience. The several blocks may be tongued and grooved together, if thought necessary.

It is not necessary here to go into a detailed description of the method of tunneling to which my improvements apply; but it will be understood that there is an outer shield, which is moved forward as the Work is done, that the masonry is built inside the tubbing, and that as the excavation proceeds the tubbing is extended by building neT sections thereon in the excavated cavity. The blocks, shaped as shown, are built up into the circle or annulus, being properly supported and held together by the tongues or hoops, .or

both. The several Wedge blocks and keys are driven into position by the jacks, thus forcing all the parts into position, so as to form a tight and permanent annulus. The hoop is then let into the slot on the exposed ends just as the inner hoop had been previously received into the inner ends of the tubbing-sections as they were brought together. Then when the masonry has been eX- tended the next section of tubbing can be put up in the same Way.

The key-block is arranged in sections which can be placed into position, the last being driven home by the jack.

I claiml. A tubbing for tunneling` purposes comprising a series of tubbing annular sections, the adjacent sections slotted to receive one and the same hoop, and each such section consisting of sectionblocks longitudinally tongued and grooved together.

2. In a tubbing for tunneling purposes, a series of annular sections joined together end to end and comprising each a series of short blocks tongued and grooved at their meeting edges, and wedge-blocks associated therewith, adapted to tighten the short blocks in the annular sections of tubbing.

3. In a tubbing for tunneling purposes, a series of annular sections suitably joined together end to end, and comprising each a series of short blocks tongued and grooved at their meeting edges, and wedge-blocks associated therewith, adapted to tighten the short blocks in the annular section of tubbing, and one of said blocks consisting of a series of short sections which can be successively placed in position.

WILLIAM S. MAGHARG.

Witnesses:

FANNY B. FAY, HOMER L. KRAFT. 

